The present invention relates generally to improvements in projectile penetration sensing targets and it relates more particularly to an improved target which produces a sharp momentary drop in the resistance between a pair of terminals when traversed by a projectile.
In U.S. Pat. Nos. 3,401,939 and 3,454,277 granted Sept. 17, 1968 and July 8, 1969 respectively to J. L. LaMura there is disclosed a projectile shorting target of the subject type in which a pair of wire screen electrodes alternate with three foamed polypropylene sheets between which they are successively sandwiched and bonded to form the target. The electrodes are connected to a resistance responsive pulsing circuit whose output is connected to a recorder. While the target devices disclosed in the above identified LaMura patents are generally satisfactory, particularly when employed with small caliber projectiles, such as rifle and pistol bullets and projectiles from various small automatic and semiautomatic weapons, even when the projectiles have thin insulating coatings, they possess important drawbacks and disadvantages, particularly when employed with large caliber projectiles, for example, 105 mm tank gun projectiles, or when struck at high angles of incidence. Under these latter conditions not only is the frequency of shorting between the electrodes after the traverse of the target by a projectile undesirably high necessitating the frequent electrical burning of the shorts or the discarding and replacement of the target but the material removed by the projectile traversing the target and the projectile itself cause excessive and irregular tearing of the exit section of the panel. Accordingly, the earlier target devices of the subject type are of limited application and often unreliable and inconvenient to use and otherwise leave much to be desired.